|Intro||Illegitimate son of Martin I the Young, King of Sicily and contender for the crown of Aragon|
|Death||29 May 1438 (Urueña, Valladolid Province, Castile and León, Spain)|
Frederic, Count of Luna (Spanish: Fadrique; c. 1401 – 29 May 1438), was a contender for the crown of Aragon.
Frederic was one of two illegitimate children recognised by King Martin the Younger of Sicily. His mother was his father's concubine, the Sicilian noblewoman Tarsia Rizzani. In 1403, Frederic and his likewise illegitimate paternal half-sister Violant were declared wards of the Crown of Aragon by their paternal grandfather, King Martin the Elder of Aragon. The royal councilor Francesc de Casasaja was ordered to bring them to Barcelona and to care for them until the King and his wife, Maria de Luna, decided "how to deal with the said son and daughter". Queen Maria, the children's grandmother, assumed the responsibility for their upbringing and education. Their illegitimate status notwithstanding, Frederic and his half-sister were the only grandchildren of the King and Queen of Aragon. The Queen died in 1406.
In 1409, King Martin the Younger died. His father's death, following the deaths of his legitimate half-brothers, left Frederic as the only living male descendant of Martin the Elder, now also king of Sicily. Martin the Elder was very fond of his grandson, but was nevertheless aware that his illegitimacy rendered his claim to the thrones of the Crown of Aragon significantly weaker, especially when compared to that of the closest legitimate agnate, Count James II of Urgell. The old king intended to ensure Frederic's accession at least to the throne of Sicily. He thus sought to have Frederic legitimated by the pope, but died from laughter a year after Martin the Younger. The question of succession not being settled yet, an interregnum ensued. In 1412, Frederic's cousin, Ferdinand of Castile, became king according to the Compromise of Caspe. The nobility of Sicily preferred Frederic to Ferdinand, but the proposal to make the former into king of an independent Sicily failed.
Frederic was created Count of Luna and made an admiral. As such, he took part in an expedition to the island of Djerba, commanded by Infante Peter, Count of Alburquerque, in 1425. He also accompanied the army of King Alfonso the Magnanimous to Castile in order to liberate the King's brother, Infante Henry, Duke of Villena.
Frederic resumed his claim to the throne in the 1430s, for which he was imprisoned and all his lands, including the County of Luna and the city of Segorb, were confiscated. He died as a prisoner.